Two-stroke internal-combustion engine



' 1,629,535 May 24, 1927. w. REHM v TWO-STROKE INTERNAL COMBUSTIONENGINE Filed Jan. 12, 1925 Patented May 24, 1927.

UNITED STATES PATENT OFFICE.

WILHELM RIEHM, OF AUGSBURG, GERMANY, ASSIGNOR TO THE FIRM: MASGHINEN-FABRIK AUGSBURG-NUERNBERG AKTIENGESELLSCHAFT, OF AUGSBURG, GER- MANY, ACORPORATION OF GERMANY.

TWO-STROKE INTERNAL-COMBUSTION ENGINE.

Application filed January 12, 1925, Serial No. 1,971, and in GermanyApril 8, 1924.

This invention relates to two-stroke internal combustion engines of thekind in which scavenging air ports are formed in the relatively thinwall of cylinder liner with the object of giving the current ofscavenging air a certain direction of movement in the interior of thecylinder. In such engines it is found that the incoming scavenging airis not given sufficient guidance by the walls of the ports with theresult that the scavenging air does not flow in the direction intended.

According to the present invention, in order to remedy theabove-mentioned defeet, guide blades are arranged in front of thescavenging air ports so as to ensure a proper guiding of the scavengingair and force the scavenging air to flow in the desired direction withinthe cylinder.

In order that the said invention may be clearly understood and readilycarried into effect-,- the same will now be described more fully withreference to the accompanying drawings in which Fig. 1 shows in crosssection an engine cylinder having two different constructions of guideblades according to this invention and Fig. 2.shows in cross section anengine cylinder with adjust-- able guide blades.

a is the cylinder liner having scavenging air admission ports I; whichfor instance are so situated that their centre lines converge to a point0. In view of the small thickness of the liner oi, the walls of theports, as aforesaid, provide an insufficient guidance for the incomingscavenging air. This is indicated at the left-hand side of the drawingwhere it will beseen that, without the present improvement, a section dof the air current passes the inner port edge e before it strikes theouter edge In order to remedy this, in front of the ports I) arearranged, in the direction of flow of the scavenglng air jets, guideblades which are either cast with the cylinder jac et as shown at theright hand side of the drawing or, as shown at the left hand side, areinserted as separate plates.

The latter construction has the advantage over the former that it ispossible to alter the angles of setting of the guide plates relativelyto the ports so that the direction of flow of the scavenging air can beregulat ed to give the greatest efiiciency. This adjustment can beeffected in a similar mann er to that of the guide blades of the wellknown Francis turbine, the individual guide pl fixed pins h a ates 9being rotatable around nd also being connected by pins and slots 2' to adisplaceable ring Z bythe ad ustment of which the said plates are turnedaround the said pins.

Having now ascertained the particularly described and nature of my saidinvention and in what manner the same is to be performed, I declare thatwhat I claim is:

1. In a two-s troke internal combustion engine, a cylinder, a liner insaid cylinder,

a reservoir for scavenging air bounded on- The foregoi Munich, Germany,this 19th day of December, 1924.

ng specification signed at DR. IVILHELM RIEHM.

